Need New Furnace/Central Air Units...Cost?

Our gas furnace/central air unit is 20 years old. We had someone come out and do a safety check and tune-up and about 35 minutes in, the technician showed me some things that showed major wear and tear and quite likely safety issues. He didn't want to go any further with a tune-up since in his opinion, it really just needs to be replaced.

We have an almost 1700 sq. ft. two-story house (with an additional 750 sq. ft. of unfinished basement). Any ballpark ideas on how much a new heating/air unit normally runs?

I always had $3-5k for an a/c unit and $7-10 for a furnace but it's been ages since I priced them. If you just need to hook things up to existing systems (no duct work...) it shouldn't be too bad. Get a secOnd opinion though. Business could just be slow for who you had come out. My 50yo furnace is going strong.

we have an 1100 sq. ft. post war single story ranch house and our gas furnace was $3400 installed, which included all new ducting. We bought a unit that would work for a tad bit larger house in case we want to add on. It is a Goodman brand, and Goodman also makes Amana, which was top rated in 2009. The Amana was about 2k more iirc. We only got quotes from local companies and none of those companies used the larger brands like Carrier, and Lennox. I think we got one quite from someone that used Trane, but it was the most expensive.

It would have been about $3000 more to add AC, which we didn't think we would need for more than maybe 20 days a year at most. We figure that it would be cheaper to add it in when and if we remodel.

Funny, I posted a similar Q a few weeks ago. I've since gotten estimates, and the lowest was $5000 for a medium quality system. I have around an 1800 sq ft house (I think!) BillK pointed out, and I've found it to be true, that if you need to go from freon (old tech) to puron (new tech) you'll need a new coil which adds $$.